The desire to extend all the benefits of broadband 3D data to 4D time-lapse surveys has been hampered by the requirement for repeatability between successive surveys. The use of deep-towed multi-sensor streamers in time-lapse acquisition creates challenges, as the existing baseline surveys will often ...
Technical Content
Internal multiple attenuation for four pre-salt fields in the Santos Basin, Brazil
Internal multiple attenuation for four pre-salt fields in the Santos Basin, Brazil
The Santos basin is known to contain strong internal multiples that pose a major challenge for the imaging of pre-salt reservoirs. Artifacts generated by incorrectly imaged internal multiples can affect model building, interpretation, and ultimately contaminate amplitudes in the pre-salt reservoirs. We examine four ...
We propose a post-migration 3D Q compensation process in the depth domain that is accurate for complex geological structures, accommodates complex Q models, and also provides flexibility in noise handling and spectral control that is critical to AVA recovery.
Imaging through near-surface absorption bodies with visco-acoustic least-squares migration: a case study from the Northern Viking Graben
Imaging through near-surface absorption bodies with visco-acoustic least-squares migration: a case study from the Northern Viking Graben
Amplitude attenuation and phase distortion of seismic data are byproducts of the Earth’s anelasticity (Q). These effects are exacerbated under regions of anomalously high absorption, such as shallow gas, causing uneven illumination and migration artifacts. We present a case study from the Norwegian North ...
3D VSP imaging under a complex salt finger at Atlantis, Gulf of Mexico
3D VSP imaging under a complex salt finger at Atlantis, Gulf of Mexico
To improve image resolution in the vicinity of the well, 3D VSP data was acquired at the Atlantis field in the Gulf of Mexico to complement the existing towed-streamer and OBN data. Two unique data challenges require special consideration and innovative techniques in order ...
Improving reflection FWI reflectivity using LSRTM in curvelet-domain
Improving reflection FWI reflectivity using LSRTM in curvelet-domain
We investigate the benefits of considering the effects of the Hessian matrix in the reflection FWI (RFWI) reflectivity, i.e., using least-squares RTM (LSRTM) to estimate the short-wavelength component of the model. In addition, a more efficient approach using single-iteration LSRTM, more specifically, using curvelet-domain ...
Correcting for salt misinterpretation with full-waveform inversion
Correcting for salt misinterpretation with full-waveform inversion
Using full-waveform inversion (FWI) to update velocity models that contain salt bodies with high velocity contrasts is challenging. It is even harder if erroneous salt geometry is part of the velocity model. Shen et al. (2017) showed a successful FWI application that corrected some ...
Image based Q-compensation for 4D reservoir identification and interpretation – A case study at Gulf of Mexico
Image based Q-compensation for 4D reservoir identification and interpretation – A case study at Gulf of Mexico
Imaged based Q-compensation coupled with FWI can solve for significant frequency and amplitude losses below shallow overburden absorptive geologic bodies. Applying Q-compensation to both the baseline and monitor 4D surveys improves the consistency of the 4D response, leading to more reliable placement of development ...
Deblending of OBN highly dense simultaneous sources acquisition offshore Indonesia
Deblending of OBN highly dense simultaneous sources acquisition offshore Indonesia
In previous publications, a hybrid deblending flow was proposed in which the last step of residual guided noise attenuation using the Noise to Signal Ratio (NSR) map was employed. This flow was proven to be effective and efficient for many OBS surveys. However, due ...